Python: streaming fix for Python: SK 0.5.0 breaks streaming #4925 (#4928)

### Motivation and Context

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Issue was raised that streaming when using chat but not a
chat_prompt_template failed because it did not return after doing the
branch for non-chat-prompt-template, this fixes that.

Fixes #4925 

### Description

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### Contribution Checklist

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- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

python/semantic_kernel/orchestration/kernel_function.py

@@ -263,6 +263,7 @@ class KernelFunction(KernelBaseModel):
                 except Exception as e:
                     # TODO: "critical exceptions"
                     context.fail(str(e), e)
+                return
 
             try:
                 chat_prompt = function_config.prompt_template